PEALD titanium nitride with direct microwave plasma
A method of depositing titanium nitride is disclosed. Some embodiments of the disclosure provide a PEALD process for depositing titanium nitride which utilizes a direct microwave plasma. In some embodiments, the direct microwave plasma has a high plasma density and low ion energy. In some embodiments, the plasma is generated directly above the substrate surface.
1 . A method of depositing titanium nitride, the method comprising sequentially exposing a substrate surface to a titanium precursor and a direct microwave plasma generated from a plasma gas by one or more microwave sources, wherein a distance between the one or more microwave sources and the substrate surface is less than or equal to 50 mm.
2 . The method of claim 1 , wherein the direct microwave plasma is generated within 20 mm of the substrate surface.
3 . The method of claim 1 , wherein the one or more microwave sources comprises an applicator with a dielectric resonant cavity.
4 . The method of claim 1 , wherein the plasma gas comprises ammonia or nitrogen gas (N 2 ).
5 . The method of claim 4 , wherein the plasma gas further comprises one or more of argon or hydrogen.
6 . The method of claim 1 , wherein a power delivered by the one or more microwave sources to the plasma gas is greater than or equal to 500 W.
7 . The method of claim 1 , wherein the substrate surface is maintained at a temperature of less than or equal to 600° C.